B1a - Fit for Life
The heart beats about 80 times per minute. When your blood pressure is taken, the results come in two readings.
When it beats, blood is forced through the blood vessels and the blood pressure is at it's highest. This is called the systolic pressure (it's the first number given)
When the heart is resting, the narrow blood vessels slow the blood flow through them, which lowers the pressure. This is called diastolic pressure. (second number given)
Blood pressure is measured in mm Hg.
Blood pressure changes all the time depending on how active you are, your age, weight, lifestyles, how much alcohol you drink, and whether you are angry.
B1a - Fit for Life
High Blood Pressure: - Weak blood vessels burst, and it damages kidneys
Low Blood Pressure: - Poor blood circulations, and dizziness and fainting
glucose + oxygen -> carbon dioxide + water + energy
Anaerobic Respiration: when you do vigorous excercise your heart and lungs cannot provide you with enough oxygen quickly enough. When this happens you cells carry out anaerobic respiration as well as aerobic respiration.
glucose -> lactic acid + energy
Lactic acid is produced because of the incomplete breakdown of glucose. The lactic acid build up in the muscles which can cause fatigue and pain.
B1b - What's for lunch?
We digest Protein into Amino Acids, Fat into glycerol and Fatty acid, and Carbs into glucose (simple sugars).
RDA in g= 0.75 x body mass in kg. (Recommended daily average)
Digestion: When food is eaten, muscles in the gut contract and push from the mouth to the anus (bum :P). It is then broken down by digestives enzymes into much smaller molecules. They can then be absorbed through the gut wall and into the blood plasma to be used by the body. This is called chemical digestion.
- Food Group Digestives Enzymes
- Protein Proteases
- Fat Lipases
- Carbohydrate Carbohydrases
B1b - What's for Lunch?
Food is kept in the stomach for several hours. Hydrochloric acid is added to the food. This kills most of the bacteria, and breaks it up further (food). The acid in the stomach also helps enzymes to work!
When in the small intestine, BILE is added (this improves fat digestion). BILE is produced by the liver, and stored in the gall bladder. When he fat breaks up, it is called emulsification.
The small molecules of food is then absorbed through the walls of the small intestine and into the blood plasma. This process happens by diffusion.
B1c - Keeping Healthy
- Beinign Tumours: Stop growing.
- Malignant Tumours: Continue to grow and spread. DANGEROUS.
- Host: a live organism that is fed upon by a parasite e.g. people
- Parasite: an organism that lives on or in another living organism causing it harm.
- Vector: an organism that transmits and carries a disease. e.g. mosquitoes.
Microorganisms can cause disease when they damage the cells in our bodies or produce poisonous chemicals in our bodies called TOXINS. These micro-organisms are calles PATHOGENS. Each PATHOGEN has its own ANTIGNEN.
Our bodies respond by producing different ANTIBODIES for each ANTIGEN. The ANTIBODY locks onto the ANTIGEN and kills the PATHOGEN.
B1c - Keeping Healthy
The problem is that it can take our bodies several days to make antibodies, and within ths time we can get very ill or even die!
Active Immunity is when the body develops immunity to ours illnesses.
Passive Immunity is when doctors inject other people antibodies into sick people to stop the illness (this doesn't last lonf though)
Antiobiotics treat bacterial and some fungal infections. In the past antibiotics were used to freely, when they weren't actually needed. This had resulted in some bacteria being immune to the antibiotics.
MRSA, is immune to almost all known antibiotics.
B1d - Keeping in Touch (Eyes and Nerves)
Binocular Vision is when you use both eyes whilst looking at the same object to judge how far away it is better.
- Iris: Controls how much light enters the eye.
- Cornea: Refracts the light
- The Lens: Focuses light onto the retina. It can also change shape when focusing. This is called accommodation.
- Optic Nerves: Carry Impulses to th Brain
- Ciliary muscle, Sclera, Fovea, Retina are also parts of the eye.
Our Nervous System consists of sensory nerves which carry info in the form of electrical impulses from the five senses to the brain and motor nerves that carry instructions to our muscles from the brain.
Each nerve consists of many nerve cells called neurones. Neurones are the longest cells in our body and can be over one metre in length. They act lick telephone wires carryinginformation and instructions to and from the brain.